Internal-combustion engine



'July 24, 1928. 1,678,221

J. B. HIRD, JR

INTERNAL COMBUSTION ENGINE Filed Sept. 5, 1924 2 Sheets-Sheet 1 NVENTORJul 24, 1928.

J. B. HIRD, JR

INTERNAL COMBUSTION ENGINE Filed Sept. 5. 1924 2 Sheets-Sheet 2 INVENTORJab/26f fl/raJi'. ATTORNEY Patented July 24, 1928.

UNITE ST ATES P T-EN OFFLC E1.

JOHN B. nm'n', JR, 0F SEATTLE, wnsmnsronfnss renon, Brnmnc'r nnnnnsnnASSIGNMENTS; To mnn Annnns'on MACHINERY corn CORPORATION.

INTERNAL-COMBUSTION"ENGINE.

This inventionreletes to improvements in two cycle internal combustionengines ofthe type embodying two piston members 'reci'p rocable onewithin the'other and thevobjects of this invention are to simplifyandcheapen the constructionand increase the efliciency of engines of thisnature;

More specificwohjects are to provide an engine having improved means forstoring and compressing a ,fuel charge; to provide an improved formof'sleeve piston having an eccentri'cally disposed enlarged portion onthe bottom'end which affords an advantageousconnection with a connectingrod, prevents turningof the sleeve piston in the cylinder and makeswitpossible to use one connecting-rod only on said sleeve piston; toprovide means for independentlylcounterbelencing each the sleeve pistonand the usual piston effecting a savingqin weight and producingan'engine' that run's very smoothly; and'to provide efficientlubricating means that will insure thorough and eflicient lubrication ofall workingpart's. o

Other, and more specific objects will be apparent from the" followingdescription taken in connection with the accompanying drawings. Y V

In thedrawings,- Figure 1 is a: vertical sectional view of an engineconstructed in accordancewith this" invention.

C =Fig. 2 is zt'vertical section of the same subs istantiallv onbrokeirllne 22 of'Flg. 1,

parts being showlrin elevation. Q i i Fig. 3 is a fragmentarysection'thviewshowing the piston members in 'an opposite position fromthat in which they are shown in Figs-1 and 2. m t a Fig. 4: is anotherfragmentary sectional view ilhistratinp, the relation hetw'een the fuelinlet and 'eXhaustports in" opening and closing 1 l Fig. 5 is a view incross sectionen broken line 5'5 of'Fig. 3 showing the-eccentric memberon the lower end of the-sleeve piston.

Referrin to 7 then drawings, throughout which like reference numeralsdesignate like parts, =6 designates-"stew; supporting an upper fr :n'ne7 whe'reon is mounted nn engine cylinder 8. The cylinder 8 is provided:with the usual weter jecket spaces ldthrough which cooling agent may becirculated by communicating pipes l'l a-nd 12 andf1s fun.

the? nr livided wilth -a!='cyliinder head; cr mp lrmincanonmed September5; 1924; -Seri'a1 No. 736,005.

13' having a suctionoperatedvvalve 14' normally urged-into aclosedposition by a 7 spring 15 for controlling the'adinission ofgaszfied fuel from a' carburetor 16. I

Thecylindero8is providedet the bottom end with an enlarged portion17arranged eccentri cajlly thereto as shown in Figs. 1 and 5; andsaid'cylinder isadapted for the recep tron of reciprocable tubularpiston. 18 herein'after termed a sleeve piston. V The sleeve piston 18is provided at its bottom end with a larger eccentric" portion 20 th atfits into'endreciprocates within the large bottom portion 17 ofthe'cylinder 8. A piston ring 22 is'provided neztr the top of the sleevepiston 18 and wnother pistomring 21 is provided near thetop end-of theenl'arge'd part 17 of said sleeve. The sleeve piston 18 isprovided withepiston headi23 which is threed'ed theretoto'make the same adjustable ifdesired. The interior of the sleeve piston: 18 is 'z tccuratelyhoredwfor the reception of a reciprocable' piston 24 of the nsualtype. pV

' A crank shaft '25 'is 'rotzitahly mounted in bearings 26 and 27inthebe'se 6 and upper housing 7 and provided with two diemetricallvopposite cri'nks 28 and conrnectedrespectively" by connecting rods 31and e2 with the sleeve piston 18mm" the otherpiston 241* Theeccentricity ofzthe enlarged bottom portion- 1 20 "of sleeve piston "18"makes it-possible to connect; the 'u'pper endof connecting rod 31 withthe interiorof fsaidj enlarged" portion 'EZOi in'steeidfof connectingthe: seine to the outside of the sleVepiS- ton as is iisua-lly "doneengines "of 1 thi ty e The ecc ntricity of portion20 also preventsrotation; on turning of the 'sleeve piston in the-c linder and: nsurespossible theuse of a: single connecting rod for the sleeve' piston"instead 'of re niringvt-wo opposite'ly disposed connecting rods tolialnnoe fliesidethr st"es ereeommonly required in ehgines o fthis'type. This form ofeennee tion' obviates themece s ity or allowingthe s1eeve+piston to project at an times below the end of the cylinderin which it reciprosettes and makes possible a shortening of osition topermit gasified fuel to enter said sleeve piston. Another port isprovided in the wall of sleeve piston 18 near theupper end and isarranged to register with a spark plug 36 when the sleeve piston '18reaches substantially it's lowermost position as shown in Fig. 3 so thatthecompressed fuel charge may be fired by the spark plug. Exhaust ports37 are provided in the walls of the sleeve piston 18 toward the lowerend thereof and are adapted to lap over and register with exhaust ports88 in the walls of cylinder 8 when the sleeve piston is at, or near, theupper limit of its stroke.

Gasified fuel for combustion purposes is drawn past valve 14 into thespace above the sleeve piston 18 thence passes through ports 40into'passageway 41 which communicates with chamber 42 and with the upper.endlof the enlarged lower end 17 of thecylinder. The sidewalls ofchamber 42 are formed of a rectangular frame 43 supported on stud bolts44 and having a cover plate 45. The required size of chamber 42 may beobtained by varying the depth of frame 43. This may be done bysubstituting'for one frame awframe of another size or by planing down aframe 43 as the tests of an engine are made until the proper adjustmentof chamber 42 is obtained.

An oil pump 46 is provided within the lowermost portion of the crankcase6 and is arranged to be driven by skew gears 47 to provide forcedlubrication for the various working parts. Oil from pump 46 is forcedupwardly through passageway 48, Fig. 2, thencethrough pipes 52 and 58 tobearings 27 and 26 respectively, thence through bores 54 and 55 to theconnecting rod hearings on cranks 30 and 28, thence through bores orconduits 56' and 57 in connecting rods 32 and 81 to the wrist pinbearings in piston 24 and enlarged sleeve portion 20. "A ver-' ticalpipe 58" connected with conduit pipe 52,

enters cylinder 8 at a point just below, the lowermost limit ofthemovement of piston ring 22 on sleeve 18 and-supplies lubricant for thesleeve pistons A shallow spiral groove 59in the sleeve piston insuresthe proper downward feed of theoil thus sup plied. I 7

A check valve 49 resiliently and-adjustably supported by a spring 50 isarranged to be opened by excess oil pressure to permit an overflowthrough port 51 in case more oil than is necessary is supplied by-pump46.

The usual' fly wheel. 60 is provided on crank shaft 25. r r r i Acounterweight'61 is provided on'crank shaft "25 at a point diametricallyopposite connecting rod bearing of crank 28 to counterbalan'ce as nearlyas possible the move ment of the sleeve piston and anothercounterweight62 is provided on the crank shaft 25 diametrically oppositeconnecting rod bearingofcrank 30 to similarly counterbalance themovement of piston 24 and rod 32. The counterweights 61 and 62 are shownto be secured to the crank shaft by U bolts 63 but obviously fmayr beintegral with said crank shaftor may be otherwise supported thereon.

These counterweights for independently counterbalancing piston 24 andsleeve 18 are important features which permit the use of a lighter flywheel and the use of a lighter frame structure for the engine; make theengine run more smoothly and generally'increase the efiiciency andreduce the'vibration ofthe same.

In operation when the sleeve piston 18 is in the uppermost position andthe piston 24 is in the lowermost position the inlet and exhaust portswill both be wide open and ga-siiied fuel underpressure will be rushinginto the sleeve piston and driving out the exhaust gases. 'As the sleevepiston 18 begins to move down and the inner piston 24 begins to move upthe inlet port 34 will first be closed as shown in Fig; 3 and theexhaust will continue until the piston 24 laps and closes the port 37,whereupon compression of the fuel gases will beginand will con"- tinueuntil the pistons 16 and 24 reach the other extreme positionshown inFig. 3 at t which time the port 35 will uncover. the

spark plug 36 and the charge will be fired.

Timing mechanism 65 will beused' to control the delivery of the sparkwhich may be deliveredjust before the point of maximum compression isreached. The gasified fuel, having entered under compression will behighly compressed at the time of the ex plosion' and the sleeve piston16- and piston 24*will be driven apart with great force causing anupwardpull onthe crank28 and a downward thrust on the crank 32,saidlpull and thrust jointly tending to impart a pow,-

erful torque to thefl crank shaft 25 and at the same time balancing"each other in such a manner as'to tendfto eliminate vibration.

As thetwo pistons, in moving apart, approach their extreme positions theexhaust ports 37 will first be uncovered allowing exhaust to begin andthe fuel inlet port 34 will then be uncovered allowing a charge ofcompressed fuel to rush'in and crowd out the .exhaustgases, the portsbeing arranged so that exhaust closes justbefore the fresh fuel beginstov pass outof the exhaust ports.

lrVhen the pistons are in the outermost ex- :treme position shown inFigs. 1 and-2 substantially-all of the gasified fuel will be expelled bythe enlarged lowerend 20 of the sleeve pistonfrom the chamber-17 and themajor portion of the ga'sified fuelwill be expelled from the upper endof the cylinder 8," but the fuel chamber 42 will always contain fuel. Assoon as the 'sleevepiston' 18 begins to move downwardly on the compression stroke a suction will be produced in the upperend of cylinder 8and in the upper portion of enlarged chamber 17 at the bottom ofcylinder 8 thus drawing in more fuel gas through carburetor 16, whichfuel gas, thus drawn in, is compressed on the next upward stroke ofsleeve piston 18 and admitted to the firing chamber as previouslydescribed.

In an engine of this type it is obviously necessary to attach theconnecting rod to the sleeve piston at a point or points re moved fromthe center. This makes it necessary either to balance the torque byproviding two oppositely disposed connecting rods, or by providing meansfor preventing the side thrust of one connecting rod from turning thepiston or tending to turn the piston and thereby producing excessivestrain in the wrist pin and connecting rod. The eccentric portion 20 ofthis engine absolutely prevents rotation of the sleeve piston and makesit possible/and practical to use a single rod and to connect the samewithin the inside of extension 20 thereby eliminat ing parts andbearings and making the en gine shorter and more compact.

The provision of the fuel pump formed by the enlarged chamber 17 andpiston section 20 at the bottom of the cylinder is essential to supplyenough fuel for the successful op eration of the engine.v

The engine may consist of as many cylinders as desired, only onecylinder being herein shown to illustrate the invention.

Obviously many changes in the invention may be resorted to within thescope and spirit of the following claims.

I claim:

1. In an engine, a cylinder having, at the lower end, an eccentricallyarranged chamber of larger diameter and having a fuel passagewayconnecting the upper end of the cylinder with the upper end of theenlarged eccentric chamber, said cylinder having exhaust ports andhaving inlet ports that communicate with said fuel passageway, a tubularpiston reciprocable in said cylinder .and having an enlargedeccentrically disposed bottom end reciprocable in said enlarged pistonchamber, said tubular piston having exhaust and inlet ports arranged toregister with the respective exhaust and inlet ports of said cylinderand another pistonrecipro' cable in said tubular piston.

2. In an engine, a cylinder having, at the lower end, an eccentricallyarranged chamber of larger diameter and having a fuel passage wayconnecting theupper end of the cylinder with the upper end of theenlarged eccentric chamber, said cylinder having exhaust ports, andhaving inlet ports that communicate with said fuel passageway, a tubularpiston reciprocable in said cylinder and hav ing an enlargedeccentrically disposed bottom end reciprocable in said enlarged pistonchamber, said tubular piston havingexhaust and inlet ports arranged toregister with the respective exhaust and inlet ports of said cylinder,another pistonreciprocable in said tubular piston, a crank shaft havingpassagewey connecting the upper end of the cylinder with the upper endof the enlarged eccentric chamber, said cylinder having ex-- haustports, and having inlet ports that communicate with saidfuel'passageway, means forming a fuel chamber communicating with saidfuel passageway, a tubular piston reciprocable in said cylinder andhaving an enlarged eccentrically disposed bottom end'reciprocable insaid enlarged piston chamber, said tubular piston having exhaust andinlet ports arranged to register with the respective exhaust and inletports of said cylinder and another piston reciprocable in said tubularpiston.

"he foregoing specification signed at Seattle,WVashington, this 13th dayof August, 1924.

JOHN B. HIRD, JR.

